noco-noco Inc. and the 3DOM Alliance Group announced that lithium-ion batteries equipped with the proprietary X-SEPA separator and a high temperature-resistant electrolyte have exceeded 2,000 cycles under 60°C conditions in ongoing charge-discharge cycle life testing. The X-SEPA is a revolutionary separator technology developed by the 3DOM Alliance Group that contributes to enhanced battery lifespan and performance. noco-noco holds an exclusive license and is working to commercialize the technology, including in Southeast Asia where countries are increasingly experiencing unprecedented heat.

Temperatures as high as 60°C significantly shorten the lifespans of conventional lithium-ion batteries. To address this issue, the 3DOM Alliance Group utilizes the X-SEPA in combination with a high temperature-resistant electrolyte, which has a high boiling point, to effectively suppress electrolyte degradation. Previously, the integration of this electrolyte into conventional lithium-ion batteries posed a challenge primarily due to its high viscosity, which rendered it incompatible with general-purpose polypropylene separators.

However, it can be used in combination with the X-SEPA separator due to the X-SEPA's highly porous structure and strong wettability of its polyimide material with organic electrolyte. Interim results of ongoing charge-discharge cycle life testing at 60°C show that batteries equipped with the X-SEPA and high temperature-resistant electrolyte demonstrate significantly higher capacity retention than batteries using a general-purpose electrolyte and separator after 2,000 cycles. The lifespan is extended by approximately five times when the battery end-of-life is set at 80% capacity retention, which is common for electric vehicle applications.

In-house testing has further confirmed that the higher boiling point of the high temperature-resistant electrolyte drastically reduces swelling in laminate battery cells when heated on a hot plate over 150°C. This addresses a critical issue that arises when battery-powered devices are exposed to high-temperature environments. The latest results demonstrate significant progress since approximately 900 cycles at the time of the previous interim results announced by 3DOM Alliance Inc. and noco-noco in April 2023. Technical experts from the 3DOM Alliance Group will present details of this research at the 2023 Fall Meeting of the Electrochemical Society of Japan to be held at Kyushu University on September 11 and 12, 2023.